1. Field of the Invention
The present invention relates to a magnetic head assembly. More particularly, the invention relates to a magnetic head assembly which is used for a magnetic, disk drive, and is made up of a slider having a magnetic head for reading data from, and writing data onto, a magnetic disk, the slider being mounted on a gimbal spring with an adhesive agent.
2. Description of the Related Art
In recent years, magnetic disk drives have been realized in ever smaller sizes and in ever lighter weights having both decreased volume and decreased height. In order to place many disks and heads in such a compact device, attempts have been made to reduce the gap among the disks and to fabricate a magnetic head-support mechanism in a small size and in a reduced thickness. Therefore, a slider for mounting the magnetic head has a decreased size in outer diameter and a decreased thickness. At present, the slider has a length, width and thickness which are all nearly halved and has a volume which is about one-eighth compared with that of sliders of ten years ago.
Even in a small and light magnetic disk drive, it has been demanded to increase the recording density of the disk accompanying an increase in the amount of data to be stored. This fact requires the gap to be narrowed between the slider mounting the magnetic head and the slider. Therefore, it has been desired to provide a slider having stabilized flying performance and, hence, to provide a slider having a more accurate shape that is little deformed by a change in the ambient temperature.
In a conventional magnetic disk drive, a magnetic disk having a diameter of, for example, 3.5 inches and a head-positioning actuator are incorporated in an enclosure. The actuator is provided with a swinging arm, and a magnetic head assembly is mounted on the tip of the arm. The magnetic head assembly is constituted by a load beam made of a stainless steel, a slider incorporating a magnetic head, and a gimbal spring interposed between the slider and the load beam.
The gimbal spring may often be provided in a tip portion of the load beam integrally therewith. In such a case, the gimbal spring is integrally formed in the load beam being partitioned by two opposing U-shaped holes formed in the tip portion of the load beam. That is the gimbal spring is supported by the load beam via a pair of beam portions formed between the opposing ends of U-shaped holes.
The slider is mounted on the gimbal spring using an adhesive agent. By using a dispenser the adhesive agent is dropwisely applied to the gimbal spring and, then, the slider is mounted being forced into contact with the adhesive agent.
As the slider is realized in a small size to satisfy the tendency toward decreasing the size and weight of the magnetic disk drive and increasing the reliability, however, the adhesion area becomes very small between the slider and the gimbal spring. This makes it difficult to accurately control the amount of the adhesive agent applied by using the dispenser. If the amount of the adhesive agent happens to become large, therefore, the adhesive agent applied to the adhesion surface of the gimbal spring spreads between the gimbal spring and the adhesion surface of the slider when the slider is adhered thereto with a pushing force. As a result, the slider is adhered to the gimbal spring over an increased area and is deformed, when the adhesive agent, is hardened.
The object of the present invention therefore is to provide a magnetic head assembly which is capable of confining the warping amount which is one of the shaping parameters of the slider that affects the floating performance within an allowable range despite a change in the temperature around the slider, in order to stabilize the floating performance of the slider. According to a first aspect of the present invention, there is provided a magnetic head assembly, comprising a slider with a magnetic head and a gimbal spring on which the slider is mounted with an adhesive agent, wherein at least a slit is formed in a slider-mounting portion of the gimbal spring opposing the adhesion surface of the slider.
In the magnetic head assembly according to the first aspect, the gimbal spring is formed integrally with the load beam or is attached to a tip portion of the load beam. When the gimbal spring is formed integrally with the load beam, the slider-mounting portion is supported by the load beam via a pair of beam portions. When the gimbal spring is attached to the tip portion of the load beam, the gimbal spring is constituted by an outer plate portion and a tongue-shape dinner plate portion surrounded by a U-shaped hole.
Depending upon the shape of the slit formed in the gimbal spring, the amount of the adhesive agent dropping on the gimbal spring can be controlled, so that the slider is suitably adhered onto the gimbal spring. According to a second aspect of the present invention, there is provided a magnetic head assembly comprising a slider with a magnetic head and a gimbal spring on which the slider is mounted with an adhesive agent, wherein the adhesive agent applied onto the adhesion surface of the slider after hardened has a Young""s modulus which is smaller than about {fraction (1/13000)} the Young""s modulus of the slider material or smaller than about {fraction (1/13000)} the Young""s modulus of the gimbal spring material. In this case, the Young""s modulus of the slider material may be nearly the same as the Young""s modulus of the gimbal spring material.
In the magnetic head assembly according to the first aspect of the present invention, the adhesive agent applied onto the gimbal spring from the dispenser is prevented from spreading beyond the slit at least one of which is formed in the gimbal spring, when the slider is adhered with pushing force and, hence, the area on which the adhesive agent is applied is limited. As a result, even when the slider and the gimbal spring have different coefficients of linear expansion, the warping amount of the slider caused by a change in the temperature can be suppressed to lie within a predetermined range since the contact area is small between the slider and the gimbal spring, and the flying height of the slider can be stabilized.
In the magnetic head assembly according to the second aspect of the present invention, the adhesive agent adhering to the slider and the gimbal spring together exhibits a very small Young""s modulus after it is hardened. Therefore, the warping amount of the slider is suppressed to a small value irrespective of a change in the temperature around the slider, and the flying height of the slider due to a change in the temperature can be stabilized.